Slitting device for bag-making machines



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W. M. SEHTZKNGER SLITTING DEVICE FOR BAG MAKING MACHINEfi Filed Nov. 5, 1925 Sweater-Sheet 1 Vt. M. SEETZHNGER SLITTING DEVICE FOR BAG MAKING MACHINES Z3 Shams-Sham 2 Filed Nov. 5 1925 Muemfoz @cfn W, E9289 W. M. SEHTZEN mama! GER SLITTING DEVICE FOR BAG MAKING MACHINES Filed Nov. 5, l

3 Sheets-Sheet 3 Patented Oct. 16, 1928.

' UNITED STATES TO MARSHALL FIELD & COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 01 ILLI- NOIS.

Application filed November 5, 1925. Serial No. 67,042.

The present invention relates to improvements in bag makmg machines and more particularly to those of the class adapted to make box bags or bags of the type produced from a paper tube having tucks in the sides wise secured to close the mouth or top of the bag. I

The primary object of the invention is to provide novel and improved slitting means whereby the slits may'be made accurately and with facility while the bag is being formed, the slittin means being applicable to bag making machines of the kind adapted to produce the bags from a paper tube and so operated that the slits will be made during the course of manufacture of the bags from the paper tube and at the proper points and of the proper length to conform with the mouths of the completed bags.

Further objects of the invention are, to provide novel and improved means for operating the slitting means whereby the timing of the operations thereof may be adjusted for making bags of differentlengths or for the production of slits of different lengths to conform with bags of different diameters; to provide means for mounting and actuating the slitting knives. whereby they may be readlly removed for sharpening and replaced; and to provide other improvements.

which will enable the slitting operation to be performed rapidly and efficiently.

To these and other ends, the invention consists in certain improvements and combinations and arrangements of parts, all as will be more fully hereinafter described, 'the features of novelty being pointed out particularly in the claims at the end of the specification ln the drawings:

Fig. 1 is a general view, in side elevation, of a bag making machine equipped with slitting means constructed in accordance with the present invention.

Fig. 2 represents on an enlarged scale and in side elevation the former and adjacentportions of the bag making machine to which the slitting means of the present 1nvent-ion is applied.

Fig. 3 is a detail view on an enlarged scale, showing the slitting means in top plan.

Fig. 4 is an end el'evatonof the structure shown in Fig. 2 as viewed from the right in said figure. Y

Fig. 5 is a detail view of the member which actuates the slitting knives.

Fig. 6 is a" detail view on an enlarged scale of the detachable pivotal mounting for one of the slitting knives.

Fig. 7 represents a cross section on the line 77 of Fig. 6. i

Fig. 8 is a perspective View of a box bag, slit at the mouth thereof to form the rate flaps.

Slitting means embodying the resent improvements is applicable generailly to bag making machines of the klIlClS wherein the bags are made from sections cut from a pa per tube, although the invention is more particularly applicable to bag making machines which produce the bags from a paper tube having tucks in its opposite longitudinal edges The preferred embodiment of the invention is shown in the present instance as applied to a bag making machine of a well known type, but it is to be understood that theinvention is not restricted to the precise construction shown, as equivalent constructions are contemplated and such will be included within the scope of the claims.

The bag making machine to which the in vention is shown applied in the present instance comprises generally a bed 1.having suitable mechanism 2 at one end thereof for feeding a paper strip 3 from which the bags are to e made to a former around which the paper strip is folded to form the tube. The former as shown comprises upper and lower plates or members 4 and 5, arran ed usually in superposed relation and suitaibly spaced apart, the member 5 having a heel 6 beneath which the paper strip 3 passes while its longitudinal edges 3 are folded upwardly, as indicated by the dotted line in Fig. 2, and as the paper strip advances through the machine, the longitudinal edges 3 of the strip are turned inwardly or toward one another and brought together above the member 4 of the former in a manner well known to those familiar with machines of this class. Paste previously applied to one of the longitudinal edges of the strip will serve to unite the edges of the strip to form a seam, and as the strip passes off of the former it is in the form of a tube. Means I 1,688,091 PATENT OPZFICE.

WILLIAM M. snrrzmena, or cnxcaeo, rumors, sssren'on', BY mnsnrl Assrenunms,

sepato the space between the upper and lower members 4 and 5 and thus operate to tuck the portions of the paper strip engaged by them into the space between the upper and lower former members. After the paper tube passes from the former, it is engaged by a pair of continuously revolving draw rolls 8, which operate to advance the paper tube continuously, and farther on the paper tube is engaged by a pair of pinch rolls 9, which grip the paper tube at the moment it is cut off from each bag length by a breaker arm 10, which swings past a cooperative knife 11. Suitable mechanism, designated by the numeral 12, is generally employed in machines of this class for folding and pasting the bottoms of the bag sections and thus completing the bags. The bag making machine just described is of a well known type extensively used in the manufacture of square bottom bags, or bags having tucks which enable them tobe opened into substantially rectangular form in cross section.

The slitting means embodying the present invention is shown applied to the former and is operative on the paper tube immediately after the latter has been formed and prior to the cutting of the bag lengths therefrom. In the particular embodiment of the invention shown, the slitting means is adapted to slit the paper tube longitudinally to the proper extent along the lines where the tucks join the upper and lower sides of the paper tube. As shown the slitting means com prises a pair of lower knives l3 and a similar pair of upper knives 14, the lower knives being mounted by the pivots 15 on the upper side of the lower folder member 5 and the upper knives being mounted on coaxial pivots 15 attached to the underside of the upper folder member 4. Each knife is provided with a cutting edge 16 which is movable by rotation of the respective knife about its pivot into a position where it pro ects beyond the longitudinal edge of the former as shown by the, full lines in Fig. 3, the knife being then in position to perform the slitting operation, and the cutting edge at other times is retracted by reverse rotation of the corresponding knife about its pivot to a position within the longitudinal edge of.the former, as indicated by the dotted lines in Fig. 3. The cutting edges of the lower and upper knives are arranged to project outwardly beyond and retracted within'the longitudinal edges of the lower and upper former members respectively although mascot thelower and upper knives are so spaced that they will accommodate between them the tucks which are formed in the opposite the tucks with the upper and lower sides ofthe tube embrace the longitudinal edges of the upper and lower former members, advancement of the paper tube along the former while the cutting edges of the knives are set to project outwardly beyond the edges of the former will cause slitting of the paper tube along the lines where the tucks join the upper and lower sides of'the tube, this slitting operation continuing while the knives are in their projected position but terminating when the knives are retracted to positions within the longitudinal edges of the former.

Means is provided for simultaneously projecting the cutting edges of the knives beyond the longitudinal edges of the former to perform the slit-ting operation on the paper tube and for retracting the knives to inter rupt the slitting operation after slits of the proper length have been formed, these operations being repeated at suitable periods during the running of the machine and While the paper tube is being advanced therethrough continuously to produce the slits at appropriate intervals in the length of the paper tube to conform with the mouths of the bags produced therefrom. The knifeactuating means in the present instance comprises ,a reciprocatory actuating bar 17, which is operatively connected to the upper and lower pairs of knives and is operated at appropriate intervals under the control of a cam. In the construction shown the actuating bar is provided with a notch 18 in which are engaged the inner ends 19 of the lower knives and a slot 20 in which are engaged the inner ends 21 of the upper pair of knives, the actuating bar being thus connected to the knives so that when the bar is reciprocated in one direction it will project the cutting edges of the knives outwardly beyond the former to perform the slitting operation, and when the bar is reciprocated in the opposite direction, it will retract the knives. The end of the knife-actuating bar which engages the knives may be guided by fitting its upper edge into a slot 22 in the upperformer member 4: and its lower edge to operate longitudinally in a slot 23 in the member 24 which supports the lower former member 5. The knives have substantially the form of bell crank levers, their inner ends extending transversely of the length of the actuating bar and their outer ends extending on an incline outwardly toward the longitudinal edges of the former so that reciprocation of the actuating bar in a direction longitudinally of the former will .or members 4 and produce movements of the outer ends of the knives to carry them outwardly beyond and retract them within the longitudinal edges of the former.

The actuating bar 17 which extends longitudinally between the upper and lower form 5 is pivotally connected at to @one arm of a bell crank lever 26, the latter being pivoted at 27 to the former support 24 and having its other arm plvotally connected at 28 to a rod 29. The upper end of this rod is pivotally connected at 3() ma lever 31, the latter being pivoted at 32 on the relatively stationary bridge 33 of the machine. The lever 31 carries a roller or projection 34, which is arranged to ride upon a cam 35, the latter being mounted on a shaft 36, which is driven continuously during the operation of the machine and in such man ner that it makes one revolution while the paper tube is being advanced to the extent of one bag length. For example, this shaft may be driven in unison from the shaft 37 which carries the breaker bar 10 through the shafts 38 and 39 and the gearing 40, 41 and 42. The cam 35 is so shaped that when the roller 34 rests on the high part thereof,

the knives will occupy their projected or slitting positions and will maintain these positions to produce slits of the desired length, and while the roller 34 is on the depressed portion of the cam, the knives will be retracted or in non-slitting position and they will remain in such position during the remainder of the advancement of the paper tube. Preferably the cam 35 is so constructed that it may be adjusted to vary the length of the slits made in the paper tube andthe spacing of the slits along the length of the paper tube to conform with bag sections of different lengths as may be cut therefrom. As shown, the cam comprises a pair of cam disks 35 and 35 which are duplicates in profile and may be relatively rotated on the shaft 36 to I increase or diminish the length of the raised portion of the cam engaged by the roller 34 as well as to time the movements of the knives into slitting and non-slitting positions. .The cam disks may be secured in different adjusted relation by a screw or bolt 43, which may be attached to one of the cam disks and extend through a segmental slot 43 in the other disk, the screW'or bolt serving to clamp the cam disks together and thus hold them in fixed relation. The pivot pin 30 which connects the rod 29 to the lever 31 may also be adjustable in a slot 44 in this lever for the purpose of adjusting the extent of movement of the knives under the action of the cam. A spring 45 is provided for holding the roller 34 in contact with the cam, this spring acting to shift the knives into retracted position as the roller 34 passes from the raised to the depressed portion of the cam.

' ranged notches 13 for resharpening, they are preferably mounted detachably on their pivots 15. Preferably and asshown, eac'h pivot is formed with ears 15 which project laterally or radially therefrom and are arranged to overlie the face of the res ective knife, and the openin in each kni e which receives its pivot 1s formed with correspondingly arare so positioned that when the knives are in operative position, they will be out of register, and hence accidental detachment of the knives is prevented. However, when it is desired to remove the knives, the actuating bar 17 is shifted longitudinally, after it has been detached from its pivot 25 and its forward end freed from the slots 22 and 23 by springing upwardly the forward end of the folder member 4, such longitudinal movement of the bar 17 serving to swing the knives until the notches 13 therein register with the ears 15 on their pivots and the inner ends of the knives become detached or disengaged from the notch 18 and the slot 20 in the bar. The knives are then released from their pivots and may be removed for sharpening. Replacement of the knives may be effected by a reversal of the operations just described.

Fig. 8 illustrates abox bag having slits in the top or mouth thereof as produced by the slitting means of the present invention. As shown, a represents the body of the bag, which is formed from the longitudinally tucked paper tube which enables the bag to be opened into substantially rectangular form, as shown. The slits designated 1) are formed longitudinally in that portion of the bag which constitutes the mouth thereof, these slits extending from the line 0 which defines the upper edge of the body of the bag to the edge of the mouth thereof, the slits thus formlng separate flaps d which may be folded individually one upon the other and pasted or otherwise secured to form a flat closure.

The mode of operation is substantially as follows:

In the operation of a bag making machine of-the well known type herein generally set forth, the paper strip 3 is drawn continuous- 1y through the machine and past the folder by the continuously revolving draw rolls 8,

and as the paper strip approaches the former,

its longitudinal edges, one of which may be supplied with paste, are turned upwardly and then folded inwardly or one upon the other, to form the strip into a tube and unite the longitudinal edges of the strip by a seam. At substantially the same time thetucking devices 7 operate on the opposite longitudinal edges of the tube being formed and .produce tucks therein which are accommodated between the upper and lower members These ears and notches off the paper tube into bag lengths.

of the bottom flaps thereof, are then performed.

The operations thus far described are those which usually take place in a bag making machine of the well known type shown.

The slitting device embodying the present invention operates at appropriate intervals on the continuously advancing paper tube to form slits therein which will conform with the slits Z) in the finished bags. The controlling cam 85 of the slitting device, wihch is driven in unison with the breaker arm 10, will make one revolution for each cut-oif operation performed by the breaker arm, and this cam is so set and adjusted that when that portion of the paper tube which is to constitute the mouth of a bag reaches the knives, the bar 17 will be forced toward the left, (Figs. 3 and 4) whereby the cutting edges 16 of all the knives will be simultaneously projected beyond the longitudinal edges of the former, and as the paper tube advances along the former, these projecting cutting edges of the knives will slit those portions of the paper tube which bend around the longitudinal edges of the upper and lower members 4 and 5 of the former, these being the portions of the paper tube which join the tucks to the upper and lower sides of the tube. The cam is so adjusted in relation to the speed at which the paper tube advances that the slits made will be of the desired length for the particular bags to be made, the slitting operation being interrupted at the proper time by the dropping of the roller 34 onto the deprsesed portion of the cam under the action of the spring 45, in consequence of which the bar 17 will be drawn towards the left in Figs. 3 and 4, thus retracting the knives to their, inoperative positions, or to points within the longitudinal edges of the former, substantially as is indicated by the dotted lines in 3. The portion of the paper tube which follows the slitted portion and which is to constitute the body. a and the bottom of the bag will thenpass the knives without being slitted. These operations of the slitting device are performed'repeatedly and at appropriate intervals with relation to the advancement of the paper tube, to form the slits in those portions of the bag lengths which are to constitute the mouths of the bags.-

The present invention provides a slitting device which is capable of use in connection with bag making mechines of the various kinds which form the bags from a paper tube, although it is particularly applicable to bag making machines of the-class in which the bagsare made from bag sections cut off from a continuously advancing paper tube having longitudinal tucks formed therein. By slitting the paper tube from which the bags are to be formed while the tube is adwancing.continuously past the former, the

slitting operation is performed without in terrupting the advance offlthe paper tube, and hence the speed of operation of the bag making machine is not reduced. The slitting of the paper tube does not interfere with the subsequent bag forming operations, as the slits are formed in the creases which join the tucks with the adjacent sides of the tube so that after the tube has been cut ofl' to form the bag sections, the slitted portion of the tubular bag section will tend to retain its fiat form and pass without difficulty between the rollers and other mechanisms used to complete the formation of the bag.

I claim as my invention 1. In combination with a bag making machine having a former for forming a tube from which the bags are to be produced, a slitting device for slitting the tube longitudinally comprising moving knives positioned inside said tubes.

2. In combination with a bag making machine embodying a former for forming a tube from which the bags are to be produced, and means for advancing the tube past the former, a slitting device operative to slit the tube longitudinally while it is advanced past the former comprising moving knives positioned inside said tubes.

3. In a bag making machine embodying means for advancing a paper'tube therein, a slitting device comprising slitting knives, located within the tube, and means for moving said knives in slitting and non-slitting relation with the tube during the advancement thereof.

4. In a bag making'machine embodying a paper tube former, and means for advancing a paper tube past it, a movable slitting device positioned inside said tube cooperative with the former and operative to slit the paper tube at intervals in its length.

5. In a bag making machine having a former for making a paper tube having longitudinal tucks therein, and means for advancing the tube, a movable slitting device operative from the inside to slit the tube at intervals in its length on the lines where the tucks join the adjacent sides of the tube.

6. In combination with a bag making machine embodying a former having relatively spaced members to receive longitudinal tucks in a paper tube and means for advancing the tube over the former, of a slitting device comprising knives mounted between said members of the former and operative outwardly to slit the portions of the tube adjacent to the edges of the said members.

7. In a bag making machine embodying a former over which a paper tube is adapted to pass and having relatively spaced members adapted to receive between them tucks formed in the opposite sides of the tube, of a slitting device comprising knives mounted between said members of the former and movable to and from positions beyond the longitudinal edges thereof.

8. In a bag making machine having means for advancing a paper tube from which bags are to be made, a slitting device comprising pivoted knives having slitting edges movable to and from slitting relation with the tube during the advancement thereof, and a reciprocating member for actuating the knives.

9. In a bag making machine having a former for making a paper tube and means for advancing the tube, a slitting device to act on the tube during its advancement past the former comprisin a slitting knife and a pivot supporting the knife and having ears to cooperate with the knife to retain it thereon, the knife having notches to prevent passage of said ears when the knife is rotated into a predetermined position and thus permit detachment of the knife from its pivot.

10. In a bag making machine, a former for the passage of a paper tube thereover, said former comprising a pair of relatively spaced members, pairs of slitting knives mounted respectively on said members and movable into and out of slitting relation with a tube passing over the former, and an actuating bar mounted to reciprocate between said members of the former and con-- nected to said pairs of knives to operate them in unison.

11. In bag making machines means forming a paper tube including a former having relatively spaced members, tucking rolls cooperating therewith and draw rolls, and a slitting knife positioned between said members and located in position to encounter the tube while passing from the tucking rolls to the draw rolls, said slitting knife being movable to and from a position intersecting the path of the tube.

12. In a bag making machine having a former for making a paper tube with creased angular corners and means for advancing said tube, a movable slitting device adapted to intersect the pat-h of said tube, positioned on the acute side of one of said angular corners, whereby the cooperative engagement between the walls of the tube adjacent the crease and the slitting device guides the tube relative to the slit-ting device to cause the slitting device to slit the tube along the crease.

In testimony whereof I have hereunto set my hand. 1

WILLIAM M. SEITZINGER. 

